
/* Copyright (c) Mark J. Kilgard, 1994. */

/**
 * (c) Copyright 1993, Silicon Graphics, Inc.
 * ALL RIGHTS RESERVED
 * Permission to use, copy, modify, and distribute this software for
 * any purpose and without fee is hereby granted, provided that the above
 * copyright notice appear in all copies and that both the copyright notice
 * and this permission notice appear in supporting documentation, and that
 * the name of Silicon Graphics, Inc. not be used in advertising
 * or publicity pertaining to distribution of the software without specific,
 * written prior permission.
 *
 * THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS"
 * AND WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR
 * FITNESS FOR A PARTICULAR PURPOSE.  IN NO EVENT SHALL SILICON
 * GRAPHICS, INC.  BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT,
 * SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY
 * KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION,
 * LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF
 * THIRD PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC.  HAS BEEN
 * ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE
 * POSSESSION, USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 * US Government Users Restricted Rights
 * Use, duplication, or disclosure by the Government is subject to
 * restrictions set forth in FAR 52.227.19(c)(2) or subparagraph
 * (c)(1)(ii) of the Rights in Technical Data and Computer Software
 * clause at DFARS 252.227-7013 and/or in similar or successor
 * clauses in the FAR or the DOD or NASA FAR Supplement.
 * Unpublished-- rights reserved under the copyright laws of the
 * United States.  Contractor/manufacturer is Silicon Graphics,
 * Inc., 2011 N.  Shoreline Blvd., Mountain View, CA 94039-7311.
 *
 * OpenGL(TM) is a trademark of Silicon Graphics, Inc.
 */

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>
#include <time.h>
#include <GL/glut.h>

#define MAXOBJS 10000
#define MAXSELECT 100
#define MAXFEED 300
#define	SOLID 1
#define	LINE 2
#define	POINT 3

GLint windW = 300, windH = 300;

GLuint selectBuf[MAXSELECT];
GLfloat feedBuf[MAXFEED];
GLint vp[4];
float zRotation = 90.0;
float zoom = 1.0;
GLint objectCount;
GLint numObjects;
struct object {
	float v1[2];
	float v2[2];
	float v3[2];
	float color[3];
} objects[MAXOBJS];
GLenum linePoly = GL_FALSE;

static void
InitObjects(GLint num)
{
	GLint i;
	float x, y;

	if (num > MAXOBJS) {
		num = MAXOBJS;
	}
	if (num < 1) {
		num = 1;
	}
	objectCount = num;

	srand((unsigned int) time(NULL));
	for (i = 0; i < num; i++) {
		x = (rand() % 300) - 150;
		y = (rand() % 300) - 150;

		objects[i].v1[0] = x + (rand() % 50) - 25;
		objects[i].v2[0] = x + (rand() % 50) - 25;
		objects[i].v3[0] = x + (rand() % 50) - 25;
		objects[i].v1[1] = y + (rand() % 50) - 25;
		objects[i].v2[1] = y + (rand() % 50) - 25;
		objects[i].v3[1] = y + (rand() % 50) - 25;
		objects[i].color[0] = ((rand() % 100) + 50) / 150.0;
		objects[i].color[1] = ((rand() % 100) + 50) / 150.0;
		objects[i].color[2] = ((rand() % 100) + 50) / 150.0;
	}
}

static void
Init(void)
{
	numObjects = 10;
	InitObjects(numObjects);
}

static void
Reshape(int width, int height)
{
	windW = width;
	windH = height;
	glViewport(0, 0, windW, windH);
	glGetIntegerv(GL_VIEWPORT, vp);
}

static void
Render(GLenum mode)
{
	GLint i;

	for (i = 0; i < objectCount; i++) {
		if (mode == GL_SELECT) {
			glLoadName(i);
		}
		glColor3fv(objects[i].color);
		glBegin(GL_POLYGON);
		glVertex2fv(objects[i].v1);
		glVertex2fv(objects[i].v2);
		glVertex2fv(objects[i].v3);
		glEnd();
	}
}

static GLint
DoSelect(GLint x, GLint y)
{
	GLint hits;

	glSelectBuffer(MAXSELECT, selectBuf);
	glRenderMode(GL_SELECT);
	glInitNames();
	glPushName(~0);

	glPushMatrix();

	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluPickMatrix(x, windH - y, 4, 4, vp);
	gluOrtho2D(-175, 175, -175, 175);
	glMatrixMode(GL_MODELVIEW);

	glClearColor(0.0, 0.0, 0.0, 0.0);
	glClear(GL_COLOR_BUFFER_BIT);

	glScalef(zoom, zoom, zoom);
	glRotatef(zRotation, 0, 0, 1);

	Render(GL_SELECT);

	glPopMatrix();

	hits = glRenderMode(GL_RENDER);
	if (hits <= 0) {
		return -1;
	}
	return selectBuf[(hits - 1) * 4 + 3];
}

static void
RecolorTri(GLint h)
{
	objects[h].color[0] = ((rand() % 100) + 50) / 150.0;
	objects[h].color[1] = ((rand() % 100) + 50) / 150.0;
	objects[h].color[2] = ((rand() % 100) + 50) / 150.0;
}

static void
DeleteTri(GLint h)
{
	objects[h] = objects[objectCount - 1];
	objectCount--;
}

static void
GrowTri(GLint h)
{
	float v[2];
	float *oldV;
	GLint i;

	v[0] = objects[h].v1[0] + objects[h].v2[0] + objects[h].v3[0];
	v[1] = objects[h].v1[1] + objects[h].v2[1] + objects[h].v3[1];
	v[0] /= 3;
	v[1] /= 3;

	for (i = 0; i < 3; i++) {
		switch (i) {
		case 0:
			oldV = objects[h].v1;
			break;
		case 1:
			oldV = objects[h].v2;
			break;
		case 2:
			oldV = objects[h].v3;
			break;
		}
		oldV[0] = 1.5 * (oldV[0] - v[0]) + v[0];
		oldV[1] = 1.5 * (oldV[1] - v[1]) + v[1];
	}
}

static void
Mouse(int button, int state, int mouseX, int mouseY)
{
	GLint hit;

	if (state == GLUT_DOWN) {
		hit = DoSelect((GLint) mouseX, (GLint) mouseY);
		if (hit != -1) {
			if (button == GLUT_LEFT_BUTTON) {
				RecolorTri(hit);
			} else if (button == GLUT_MIDDLE_BUTTON) {
				GrowTri(hit);
			} else if (button == GLUT_RIGHT_BUTTON) {
				DeleteTri(hit);
			}
			glutPostRedisplay();
		}
	}
}

static void
Draw(void)
{
	glPushMatrix();
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluOrtho2D(-175, 175, -175, 175);
	glMatrixMode(GL_MODELVIEW);
	glClearColor(0.0, 0.0, 0.0, 0.0);
	glClear(GL_COLOR_BUFFER_BIT);
	glScalef(zoom, zoom, zoom);
	glRotatef(zRotation, 0, 0, 1);
	Render(GL_RENDER);
	glPopMatrix();
	glutSwapBuffers();
}

static void
DumpFeedbackVert(GLint * i, GLint n)
{
	GLint index;

	index = *i;
	if (index + 7 > n) {
		*i = n;
		printf("  ???\n");
		return;
	}
	printf("  (%g %g %g), color = (%4.2f %4.2f %4.2f)\n",
	       feedBuf[index],
	       feedBuf[index + 1],
	       feedBuf[index + 2],
	       feedBuf[index + 3],
	       feedBuf[index + 4],
	       feedBuf[index + 5]);
	index += 7;
	*i = index;
}

static void
DrawFeedback(GLint n)
{
	GLint i;
	GLint verts;

	printf("Feedback results (%d floats):\n", n);
	for (i = 0; i < n; i++) {
		switch ((GLint) feedBuf[i]) {
		case GL_POLYGON_TOKEN:
			printf("Polygon");
			i++;
			if (i < n) {
				verts = (GLint) feedBuf[i];
				i++;
				printf(": %d vertices", verts);
			} else {
				verts = 0;
			}
			printf("\n");
			while (verts) {
				DumpFeedbackVert(&i, n);
				verts--;
			}
			i--;
			break;
		case GL_LINE_TOKEN:
			printf("Line:\n");
			i++;
			DumpFeedbackVert(&i, n);
			DumpFeedbackVert(&i, n);
			i--;
			break;
		case GL_LINE_RESET_TOKEN:
			printf("Line Reset:\n");
			i++;
			DumpFeedbackVert(&i, n);
			DumpFeedbackVert(&i, n);
			i--;
			break;
		default:
			printf("%9.2f\n", feedBuf[i]);
			break;
		}
	}
	if (i == MAXFEED) {
		printf("...\n");
	}
	printf("\n");
}

static void
DoFeedback(void)
{
	GLint x;

	glFeedbackBuffer(MAXFEED, GL_3D_COLOR, feedBuf);
	(void) glRenderMode(GL_FEEDBACK);

	glPushMatrix();

	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluOrtho2D(-175, 175, -175, 175);
	glMatrixMode(GL_MODELVIEW);

	glClearColor(0.0, 0.0, 0.0, 0.0);
	glClear(GL_COLOR_BUFFER_BIT);

	glScalef(zoom, zoom, zoom);
	glRotatef(zRotation, 0, 0, 1);

	Render(GL_FEEDBACK);

	glPopMatrix();

	x = glRenderMode(GL_RENDER);
	if (x == -1) {
		x = MAXFEED;
	}
	DrawFeedback((GLint) x);
}

/* ARGSUSED1 */
static void
Key(unsigned char key, int x, int y)
{

	switch (key) {
	case 'z':
		zoom /= 0.75;
		glutPostRedisplay();
		break;
	case 'Z':
		zoom *= 0.75;
		glutPostRedisplay();
		break;
	case 'f':
		DoFeedback();
		glutPostRedisplay();
		break;
	case 'l':
		linePoly = !linePoly;
		if (linePoly) {
			glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
		} else {
			glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
		}
		glutPostRedisplay();
		break;
	case 27:
		exit(0);
	}
}

/* ARGSUSED1 */
static void
SpecialKey(int key, int x, int y)
{

	switch (key) {
	case GLUT_KEY_LEFT:
		zRotation += 0.5;
		glutPostRedisplay();
		break;
	case GLUT_KEY_RIGHT:
		zRotation -= 0.5;
		glutPostRedisplay();
		break;
	}
}

int
main(int argc, char **argv)
{
	glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE);
	glutCreateWindow("Select Test");
	Init();
	glutReshapeFunc(Reshape);
	glutKeyboardFunc(Key);
	glutSpecialFunc(SpecialKey);
	glutMouseFunc(Mouse);
	glutDisplayFunc(Draw);
	glutMainLoop();
	return 0;             /* ANSI C requires main to return int. */
}
